The present invention relates generally to closed-volume systems such as those used in liquid cooling systems. More particularly, the present invention is directed to methods for detecting a leak in a closed-volume system.
Closed-volume liquid systems include a pump that operates to circulate a fluid through a loop having a fixed volume at constant temperature. The volume varies only with thermal contractions and expansions due to temperature fluctuations. The pump includes a pumping mechanism, such as an impeller, that receives low pressure fluid at an inlet and produces high pressure fluid at an outlet. Closed-volume liquid systems are often configured to circulate fluid through various components in aircraft systems. Sometimes the components are critical to controlling and maintaining flight of the aircraft and require prolonged cooling to function. It is imperative to maintain functionality of the components even after a leak in the system occurs. It is therefore desirable to detect and isolate leaks in closed-volume systems as quickly as possible before a significant volume of the fluid is lost and operation of the system can no longer be maintained. Furthermore, leaked fluids from the closed-volume systems can become a fire hazard or can cause interference with operation of electrical equipment. It is therefore desirable to quickly detect and isolate a leak in a closed-volume system.
Many closed-volume liquid systems include control systems that execute leak detection logic. The control system monitors conditions of the closed-volume system that are indicative of the liquid in the system. Level sensors can be provided in the liquid system to directly provide an indication that fluid from the system has been lost. Also, pressure sensors are positioned at various places in the loop that provide an indication of the performance of the pump. If pressures in the loop fall below prescribed levels, it is an indication that a leak exists in the system. Typical leak indicators such as level and pressure are not always reliable for every pump condition and may sometimes provide inaccurate readings. There is, therefore, a need for improved leak detection logic in closed-volume systems.